| 摘要 |
PURPOSE:To realize the ignition lead angle characteristic of complex function employing the engine rotary speed and the intake negative pressure as two variables through simple structure by providing a circuit for producing two ramp signals of such waveform as will transit linearly or obliquely in synchronization with a referential pulse. CONSTITUTION:Referential pulse generating means 10 for receiving a signal from a pickup comprised of a rotor 1a and a coil 1b to be rotated through an engine and first and second ramp signal generating circuits 30, 40 for repeatedly producing the ramp signals R1, R2 of such waveform as will transit linearly and obliquely in synchronization with the referential pulse RP are provided. Then said ramp signals R1, R2 are compared to determine the ignition timing through ignition timing determination circuit 80. The ramp signal generating circuit 40 is constituted with time limit setting means 50 for determining the rising time limit and the inclination of signal R2 corresponding with respective engine speed point Ni and negative pressure control means 60 for controlling the shape of the signal R2 with correspondence to the output from the negative pressure signal generating means 20. |
